IOWA CITY, Ia. — The first time Peyton Mansell took a snap under center in live drills instantly became a legendary Iowa football practice story.

It was last August, and the freshman quarterback from Texas was thrust into a 9-on-7 situation. It’s always a run play in 9-on-7 — not a real high-pressure spot.

Even though he exclusively took shotgun snaps in high school, Mansell knew what he was getting into with Iowa’s pro-style scheme. He had practiced taking snaps under center.

“I don’t know why everyone’s making such a big deal about this,” he remembered thinking. “Then that first live (drill), it was just a different speed. And I was not ready for it.”

First snap, he fumbled.

Second snap, he fumbled.

Third snap … Mansell tumbled backwards to the ground after the center stepped on his foot.

A disastrous, humbling sequence that got him kicked out of the drill that day.

But it has become a humorous story now, to both him and Iowa’s coaches, because of the progress Mansell revealed over the 12 months that followed.

“It was comical how bad I was at one point,” he said at Friday's media day as a quarterback now entering his second year in a Power Five program and second year grasping Brian Ferentz’s offense. “Just the improvement I’ve gotten literally from taking a snap under center is astounding to me.”

That’s good news, because Mansell is at the fore-front of what has become one of least-discussed dilemmas of Iowa’s fall camp that coaches are feverishly trying to figure out.

The battle to become Iowa’s backup quarterback.

As Friday’s media-day interviews with assistant coaches wrapped up, Iowa's offensive coordinator seemed astounded that he finally got his first question about who would be No. 2 behind unquestioned starter Nate Stanley.

Mansell or true freshman Spencer Petras?

“That’s got to be a question, right?” Ferentz said.

Ferentz divulged that he’s been thinking about the backup-QB situation a lot lately. He compared it to a year ago at this time, when Stanley and Tyler Wiegers were in a heated camp battle to become Iowa’s starter.

Wiegers and Ryan Boyle have since transferred, leaving two freshmen as the lone combatants to be backup.

“The good news is,” Ferentz said, “I’d rather be talking about the backup quarterback (competition). The frightening thing is, that guy’s one bullet away.”

The last time a No. 1 quarterback missed a game due to injury was when C.J. Beathard started in place of Jake Rudock at Purdue on Sept. 27, 2014.

But coaches at every level always worry about losing their QB1 for even a short amount of time. The entire offense — especially at Iowa — relies on precision timing and that player's mastery of the playbook.

if something happened to Stanley, how big would the drop-off be? Certainly not as steep as it would’ve been in the spring.

Quarterbacks coach Ken O’Keefe has been impressed at the fast pace at which Mansell and Petras have grown. Head coach Kirk Ferentz said the battle is on “an even playing field right now.”

Mansell and Petras have been splitting No. 2 reps down the middle in practice. Every throw is analyzed. Every classroom session is magnified.

“These guys haven’t been here that long. They’re babies in a lot of ways,” O’Keefe said. “But you’ve got to get them ready. They’re moving along at a pretty good clip right now.”

Mansell is probably further along with his understanding of the offense; he’s been here seven months longer than Petras, who early-enrolled in January. At 6-foot-2, 210 pounds, Mansell has more elusiveness in the pocket than Petras or even Stanley.

He's got a little Drew Tate vibe to him.

"Using my feet to extend plays as long as possible leads to the best plays sometimes,” Mansell noted.

Petras, meanwhile, has shown considerable improvement since that Friday night in April. At 6-5, 227, the 18-year-old Californian has a powerful arm and showed good touch on his throws during Saturday’s Kids Day open practice.

The whole situation is reminiscent of 2016, when Iowa chose a true freshman (Stanley) by a nose over an older player (Wiegers) to take the No. 2 job at the end of fall camp.

Stanley would be thrust into action for a series against North Dakota State, when C.J. Beathard dinged his shoulder, but barely played beyond that.

Yet there’s not quite as much urgency to establish a clear-cut pecking order this year, because of the NCAA’s new red-shirt rule that allows a player to preserve a year of eligibility if he plays in four or fewer games. That’s something the entire offensive staff is mulling with Petras.

“If Petras won the job, there’s a chance he could still redshirt,” Brian Ferentz said. “If he wins the job, we would still try to get him in the game whenever we could. You look back in Nate’s scenario (in 2016), if we had (these) rules, we may have gone in a little different direction.”

So, this could be an evolving conversation as the season goes on. Even if Petras is the guy Week One, Iowa might prefer to take steps to make sure he’s a red-shirt freshman (and not a true sophomore) in 2019.

But there’s still urgency to make a decision. Because if Stanley goes down, somebody’s got to go in there.

Mansell said the competition hasn’t been cut-throat, by any means. And with Stanley's help, both guys are progressing as fast as they can.

“Year 1 to Year 2, I feel like a completely different player,” Mansell said. “Everything is so much more comfortable.

“I actually understand things now. … I know we’re doing this because the defense gave us this. I really feel like I’m getting to the point mentally where I could be helping out.”

Hawkeyes columnist Chad Leistikow has covered sports for 23 years with The Des Moines Register, USA TODAY and Iowa City Press-Citizen. Follow @ChadLeistikow on Twitter.